1. Field of the Invention
The present invention relates to resource virtualization. In one example, the present invention relates to methods and apparatus for efficiently virtualizing, allocating, and managing resources used to connect servers to storage area networks.
2. Description of Related Art
Conventional servers connect to storage area networks such as fibre channel fabric storage area networks using host bus adapters (HBAs). In many implementations, multiple HBAs are included in each server to provide for redundancy and load sharing. Each HBA is connected to a fibre channel switch port. If many servers are connected to a storage area network, a large number of HBAs and fibre channel switch ports are required. A large number of HBAs and fibre channel switch ports are required even though many HBAs and switch ports remain underutilized.
Some virtualization work has been done to provide shared access to a fibre channel storage area network within a particular server. Multiple operating systems included on a server may have limited shared access to a fibre channel storage area network. N-port virtualization in fibre channel allows for multiple initiators in a single HBA within a single server. Some solutions have allowed sharing of connectivity using gateway techniques through Ethernet. However, these solutions are high latency and low bandwidth, often unsuitable for typical storage area network applications and data center applications.
However, techniques and mechanisms for sharing resources such as HBAs and sharing connectivity to fibre channel storage area networks are limited. In many instances, conventional mechanisms still lead to underutilization and resource inflexibility. Network administration issues also remain complicated with the need for a large number of HBAs and switch ports. Consequently, it is desirable to provide methods and apparatus for more efficiently connecting servers to fibre channel storage area networks.